Yarn guiding device for machine winding cross wound bobbins

ABSTRACT

A double cam groove roll for imparting a traverse movement to a yarn guide has grooves that meet at their ends at substantially the same angle at which they cross elsewhere. The cam groove follower has a pivotal mounting and is of elongated form with rounded ends. The outer surfaces of the grooves where they run into each other are flared to provide a partial cup surface into which one end of the follower will seat and swing in that seat as a socket, while the opposite inner surfaces of the grooves are flared out to form a concave surface opposite said cup surface adapted to permit the other end of the follower to flop quickly over against the outer surface of the in-running groove. The cup or socket surface may be a spring loaded replaceable insert and the cam groove follower may have spring loaded end pieces seated in an intermediate pivotal body.

[ Oct. 30, 1973 YARN GUIDING DEVICE FOR MACHINE WINDING CROSS WOUND ROBBINS [75] Inventor: Emil Keller, Wadenswil,

Switzerland [73] Assignee: Maschinenfabrik Schweiter AG, l-lorgen, Switzerland [22] Filed: June 19, 1972 [21] Appl. No.: 263,982

3,612,428 10/1971 l-lalske ..242/43X Primary ExaminerStanley N. Gilreath AttorneyFlynn & Frishauf [57] ABSTRACT A double cam groove roll for imparting a traverse movement to a yarn guide has grooves that meet at their ends at substantially the same angle at which they cross elsewhere. The cam groove follower has a pivotal mounting and is of elongated form with rounded ends. The outer surfaces of the grooves where they run into each other are flared to provide a partial cup surface into which one end of the follower will seat and swing in that seat as a socket, while the opposite inner surfaces of the grooves are flared out to form a concave surface opposite said cup surface adapted to permit the other end of the follower to flop quickly over against the outer surface of the inrunning groove. The cup or socket surface may be a spring loaded replaceable insert and the cam groove follower may have spring loaded end pieces seated in an intermediate pivotal body.

6 Claims, 4 Drawing Figures YARN GUIDING DEVICE FOR MACHINE WINDING CROSS WOUND ROBBINS This invention relates to yarn guiding devices for a machine winding of cross wound bobbins and more particularly to yarn guiding devices having a yarn guide movable back and forth on a guide rail or track and adapted to be driven by a double groove cam roll and a cam groove follower.

In known devices of this type the cam groove follower and the yarn guide propelled by the follower travels from one end of the roll to the other and back as the cam groove roll rotates. To reverse the travel of the cam groove follower from one direction to the opposite direction, the out-running groove is swung away from its original direction in a turn around curve which leads into the in-running groove. Such groove rolls are accordingly referred to as traverse rolls or traverse winding rolls.

Such a yarn guiding device exhibits serious disadvantages. The high degree of wear of the follower and of the outer rolls of the turn around curve, for example, resulting from the high friction arising there is a drawback. Another drawback is the relatively long dwell of the yarn guide in the turn around region, because the radius of the turn around curve has a certain minimum value and must be made greater and greater the higher the speed of revolution of the roll.

It is an object of the present invention to avoid the disadvantages just mentioned and to provide a yarn guiding device which allows an increase of the velocity of yarn lay with a shortening of the relative dwell time of the yarn guide in its reversing region and a reduction of the amount of wear that arises on reversals.

SUBJECT MATTER OF THE PRESENT INVENTION:

Briefly, the out-running and in-running grooves from which and to which the follower must be guided, are joined at the roll ends by a flared, partial cup surface to form a rounded corner. The cup surface may be formed by smoothly cutting a portion of the groove. The resulting concavely curved surface permits an elongated groove follower to flip over from the direction of the out-running groove to the direction of the in-running groove.

The relative dwell time of the yarn guide at the reversal region becomes a minimum, because the follower is not, as before, steered gradually around while maintaining its direction of motion relative to the groove, but rather flops over from the out-running groove into the in-running groove with a rapid reversal of its direction of motion. Even apart from the greater velocities of operation of the yarn guiding device now possible, it is now feasible to obtain significantly more precise end surfaces of the bobbins, since the bobbin edge, as a result of the relatively short dwell times of the yarn guide at these places is required to pick up less yarn than before and thus becomes softer.

Illustrative embodiments of the invention are described in greater detail by reference to the drawing in which:

FIG. 1 is a schematic perspective view of a yarn guiding device;

FIG. 2 shows in detail the mechanism shown in FIG. 1 but developed, and on a larger scale;

FIG. 3 is a modified form of a portion of the mechanism shown in FIG. I; and

FIG. 4 is a modification of another portion of the mechanism shown in FIG. 1.

As shown in FIG. 1, the yarn guiding device for machine winding of cross wound bobbins comprises a yarn guide 1 which is movable back and forth along a guide rail 2 over the entire width of the bobbin to be wound. The back and forth movement of yarn guide 1 is produced by a motor driven double groove cam roll 3 acting on a cam groove follower 5 pivotally mounted on an axle 4 extending below the yarn guide ll. This follower 5 slides in the grooves 6 and 7 of the roll 3. As shown in the drawing, where the arrow 8 indicates the direction of rotation, the groove 6 is shown as the outrunning groove and the groove 7 as the in-running groove. In FIG. I the follower 5 is shown in one of its node positions which corresponds to a traverse reversal position of the yarn guide 1 at the corresponding end of the bobbin being wound. The same arrangements and effects are also present at the right-hand end of the roll 3 shown in the drawing.

As may further be observed in FIG. 1, on both ends of the groove roll 3, the out-running groove meets the in-running groove at a particular angle, usually rather sharp, and in each case the two outer groove edges 9 and 10 form a partial cup surface or socket 11, as is shown particularly clearly at the right end of the groove roll 3. The sockets I! serve to seat a correspondingly curved end surface of the follower 5 when it arrives, as shown at the left end of the drawing in FIG. 1. The groove edges 12 and 13 opposite the socket 11, on the other hand, are joined by a common curved guiding surface 14 which is concave with respect to the follower path, in order to permit a swinging around of follower 5 about the pivot provided by socket l l. The distance between socket l1 and guide surface 14, accordingly, corresponds to the length dimension of follower In FIG. 2 development of the movement of follower 5 in the reversal portion of its path in accordance with the embodiment just described is set forth to make clear what occurs in the device of FIG. 1 during reversal. For the purpose of clearer explanation, the elements are shown as if the grooved roll were standing still and the guide rail 2 were moving relative to it. The solid lines show follower 5 at the center position of its reversal or traverse node, whereas the dashed lines show other positions of follower 5 and guide rail 2 in the movement of the follower in the direction of the arrows, both before and after the center position. As shown the advancing follower 5 engages its forward end, as defined by its direction of motion, in socket 11 at the end of out-running groove 6 and is then swung around counter-clockwise about the pivot so formed, whereupon follower 5, with its longitudinal axis flopped over, is then moved into the in-running groove 7, with the other end surface of the follower becoming the forward end in the new direction of motion.

From the foregoing it should be clear that the dwell time of the follower in the reversal region described is small as a result of its momentary flop-over from outrunning to in-running groove upon reversal of its relative direction of motion and much smaller as was the case when the follower had to slide around a long drawn-out curve in this area. This enables, as previously mentioned, greater operating velocities of the yarn guiding device to be realized and in addition permits controlled bobbin end surfaces to be wound.

For damping the impact shock of the arriving follower 5 on the seating surfaces of socket 11 the latter may, as shown in FIG. 3, be provided with a replaceable insert seated against a spring 15 providing a resilient backing.

Follower 5 may, for the same purpose, be constructed, as shown in FIG. 4, with end pieces 18 and 19, spring mounted by springs and 21 respectively on a central body or carrier 16 and connected together by a rod or pin 17 passing through carrier 16. Here also the curved end surfaces of end pieces 18 and 19 will correspond to the curvature of the seating surfaces of sockets 11.

Various changes and modifications may be made -within the inventive concept.

I claim: 1. A yarn guiding device for machine winding of cross wound bobbins comprising:

a yarn guide movable back and forth over the entire width of the bobbin on a guide rail or track;

a double worm cam groove traverse roll and driving means therefor;

an elongated cam groove follower;

said cam groove follower being pivotally mounted intermediate its ends to said yarn guide for transmitting reciprocating motion from said roll to said yarn guide;

the respective grooves of said double cam groove roll merging with each other at their extremities at a predetermined angle and at such place the respective outer sides of said grooves are flared into each other to form a partial cup surface suitable for seating an end surface of said follower, and

the two groove edges opposite said cup surface lead into each other over a concavely curved surface adapted to permit said follower to swing over from one groove to the other about the socket pivot formed by the seating of said end surface of said follower in said cup surface.

2. A thread guiding device as defined in claim 1, in which said cup surface is provided by a replaceable spring loaded insert.

3. A thread guiding device as defined in claim I, in which said cam groove follower is of composite construction comprising spring loaded end pieces seated in an intermediate portion.

4. A thread guiding device as defined in claim 1, in which said cam groove follower has curved end surfaces corresponding to the said cup surface so as to fit therein over an angular range of positions.

5. A thread guiding device as defined in claim 1, wherein at least a portion of the cup surface is resilient.

6. A thread guiding device as defined in claim 1, wherein the cam groove follower is longitudinally located in said grooves; and said cup shaped surface and said concavely curved surface are spaced by at least the length of the follower and provide, conjointly, reversing guide surfaces for said elongated follower to flip over from the direction of the out-running worm cam groove and into the in-running worm cam groove and thus provide for quick reversal of direction of cam follower movement. 

1. A yarn guiding device for machine winding of cross wound bobbins comprising: a yarn guide movable back and forth over the entire width of the bobbin on a guide rail or track; a double worm cam groove traverse roll and driving means therefor; an elongated cam groove follower; said cam groove follower being pivotally mounted intermediate its ends to said yarn guide for transmitting reciprocating motion from said roll to said yarn guide; the respective grooves of said double cam groove roll merging with each other at their extremities at a predetermined angle and at such place the respective outer sides of said grooves are flared into each other to form a partial cup surface suitable for seating an end surface of said follower, and the two groove edges opposite said cup surface lead into each other over a concavely curved surface adapted to permit said follower to swing over from one groove to the other about the socket pivot formed by the seating of said end surface of said follower in said cup surface.
 2. A thread guiding device as defined in claim 1, in which said cup surface is provided by a replaceable spring loaded insert.
 3. A thread guiding device as defined in claim 1, in which said cam groove follower is of composite construction comprising spring loaded end pieces seated in an intermediate portion.
 4. A thread guiding device as defined in claim 1, in which said cam groove follower has curved end surfaces corresponding to the said cup surface so as to fit therein over an angular range of positions.
 5. A thread guiding device as defined in claim 1, wherein at least a portion of the cup surface is resilient.
 6. A thread guiding device as defined in claim 1, wherein the cam groove follower is longitudinally located in said grooves; and said cup shaped surface and said concavely curved surface are spaced by at least the length of the follower and provide, conjointly, reversing guide surfaces for said elongated follower to flip over from the direction of the out-running worm cam groove and into the in-running worm cam groove and thus provide for quick reversal of direction of cam follower movement. 